INTERNATIONAL JOURNALOF SYSTEMATIC BACTERIOLOGY,Apr. 1984, p. 268-269 Vol. 34, No. 2 0020-7713/84/020268-02$02.OO/O Copyright 0 1984, International Union of Microbiological Societies

Proposal to Reject the New Combination Yersinia pseudotuberculosis subsp. pestis for Violation of the First Principle of the International Code of Nomenclature of Bacteria Request for an Opinion

JAMES E. WILLIAMS Department of Hazardous Microorganisms, Walter Reed Army Institute of Research, Washington, D.C. 20307

It is proposed that the name Yersinia pseudotuberculosis subsp. pestis, for the organism also known by the valid name Yersinia pestis, violates Principle 1, Subprinciple 2, of the International Code of Nomenclature of Bacteria and should be rejected.

The Approved Lists of Bacterial Names (5) includes concept. This question is trivial and academic compared Yersinia pestis (Lehmann and Neumann 1896) van Loghem with the practical hazards that attend acceptance of subspe- 1944 for the causative agent of plague and Yersinia pseudotu- cies rank for Y. pestis. Although deoxyribonucleic acid berculosis (Heiffer 1889) Smith and Thal 1965 for the caus- homology data have come to be generally accepted as ative agent of pseudotuberculosis. In 1981, the new combi- evidence for species membership, it might be argued that in nation Yersinia pseudotuberculosis subsp. pestis (Lehmann this exceptional case the highly infectious characteristic, and Neumann) Bercovier et al. 1981 was validly published which differentiates these two distinct entities, is of suffi- for the pathogen of plague (3). As a consequence, a subspe- cient scientific and practical importance to merit recognition cies was automatically created for the pseudotuberculosis at the species level. In this case a ruling to conform to the bacillus, giving Yersinia pseudotuberculosis subsp. pseudo- First Principle of the International Code of Nomenclature of tuberculosis (Pfeiffer) Smith and Thal 1965. The new names Bacteria could be of critical importance. do not invalidate the earlier names (4),so there are presently My position is that Y.pestis is the only suitable name for two valid ways to refer to each of these human pathogens. the plague bacillus strictly as a matter of nomenclature and Uncertainty has arisen about which names should be used that the accepted official use of that name, conserved for (2). In fact, it now depends upon personal preference or reasons of human safety, does not negate or reflect in any institutional policy. The Centers for Disease Control in the way upon the close genetic and taxonomic relationships that lJnited States continue to use the older names (2), whereas have been established between Y.pseudotuberculosis and Y. the World Health Organization is using the newer names (6, pestis (1). 7). In summary, the name Y.pseudotuberculosis subsp. pes- Plague is now being reported as a disease arising from tis can cause confusion with dire consequences for public infection with both Y.pestis and a subspecies of Y.pseudo- health. Principle 1, Subprinciple 2, of the International Code titberculosis. As a result, considerable confusion can arise of Nomenclature of Bacteria is to “avoid or reject the use of about what constitutes a focus of pseudotuberculosis infec- names which may cause error or confusion,’’ and General tion. Some regions with plague that are free of the disease Consideration 6 of the Code indicates that Principles take called pseudotuberculosis have suddenly become endemic precedence over the Rules (4). Avoidance of this new name for Y.pseudotuberculdsis, if one prefers the newer terminol- for the plague bacillus would probably prove ineffective. The ogy. More importantly, use of the new names may cause potential for life-threatening mishaps would persist long into errors leading to accidental plague infections that could the future. Should an accident occur, the scientific commu- threaten public health and cost lives (6). Such accidents nity and public health officials could be discredited for might arise by misreading labels on plague cultures that creating a human hazard that was foreseen (1, 2) and should properly list the new name or from labels on plague cultures have been prevented. Therefore, it is respectfully requested that omit, or have lost, the subspecies epithet pestis. This that the Judicial Commission, as the responsible authority, potential will be exacerbated if the name Y.pseudotubercu- issue an Opinion to reject the name Yersinia pseudotubercu- his continues to be used without a subspecies epithet, as losis subsp. pestis for violation of the First Principle of the there will be less tendency to question and identify misla- Code. beled cultures of the plague bacillus. In effect, authorities who recommend use of Y. pseudotuberculosis without a subspecies epithet are inadvertently contributing to the LITERATURE CITED potential for laboratory accidents. A nomenclatural consideration is that is the type 1. Bercovier, H., H. H. Mollaret, J. M. Alonso, J. Brault, G. R. Y.pestis Fanning, A. G. Steigerwalt, and D. J. Brenner. 1980. Intra- and species of the genus. Subordination of the type specific interspecies relatedness of Yersinia pestis by DNA hybridization epithet might affect the validity of the genus depending upon and its relationship to Yersinia pseudotuberculosis. Curr. Micro- whether the epithet or the genetically homologous cultures biol. 4:225-229. themselves are considered to represent the type species 2. Brenner, D. J., J. C. Feeley, andR. A. Feldman. 1982. Confusion in bacterial nomenclature. ASM News 48511-512. 3. International Journal of Systematic Bacteriology. 1981. Validation * Corresponding author of the publication of new names and new combinations previous- 268 VOL. 34, 1984 PROPOSAL TO REJECT Y. PSEUDOTUBERCULOSZS SUBSP. PESTZS 269

ly effectively published outside the IJSB. List no. 7. Int. J. Syst. 1980. Approved lists of bacterial names. Int. J. Syst. Bacteriol. Bacteriol. 31:382-383. 30:225-420. 4. Lapage, S. P., P. H. A. Sneath, E. F. Lessel, V. B. D. Skerman, 6. Williams, J. E. 1983. Warning on a new potential for laboratory- H. P. R. Seelinger, and W. A. Clark (ed.). 1975. International acquired infections as a result of the new nomenclature for the code of nomenclature of bacteria. 1975 Revision. American plague bacillus. Bull. W. H. 0. 61545-546. Society for Microbiology, Washington, D.C. 7. World Health Organization. 1981. Weekly Epiderniol. Rec. 5. Skerman, V. B. D., V. McGowan, and P. H. A. Sneath (ed.). 50:400.